Make hardening work with all db/schema managers

Previously, hardening only worked with databases, not with schemas. Also test that hardening works with all relevant db managers.

src/Database/TenantDatabaseManagers/TenantDatabaseManager.php

@@ -37,4 +37,9 @@ abstract class TenantDatabaseManager implements StatefulTenantDatabaseManager
 
         return $baseConfig;
     }
+
+    public function getCurrentDatabaseName(Connection $connection): string
+    {
+        return $connection->getDatabaseName();
+    }
 }